The backbone of the Internet was originally a series of high-speed links between major supercomputer sites and educational and research institutions within the U.S. and throughout the world. A major part of it was the NFSNet, managed by the U.S. National Science Foundation. In 1995, large commercial Internet providers (ISPs), such as MCI, Sprint and UUNET, took responsibility for the Internet backbones and have increasingly enhanced their capacities. Regional ISPs link into these backbones to provide lines for their subscribers, and smaller ISPs hook either directly into the national backbones or into the regional ISPs.

Although most new users interact with the Internet via their Web browsers, for years, command-line UNIX utilities have been used. For example, an FTP (File Transfer Protocol) program allows files to be downloaded, and the Archie utility provides listings of these files. Telnet is a terminal emulation program that lets you log onto a computer in the Internet and run a program. Gopher provides hierarchical menus describing Internet files (not just file names), and Veronica lets you make more sophisticated searches on Gopher sites.